The Zika virus is associated with rare birth defect microcephaly, but no causal connection has yet been established and anomalies keep cropping up. Though much of Latin America is plagued with the mosquito-borne Zika virus, the vast majority of the birth defects are found in Brazil. And a significant number of microcephaly cases are being found with patients that never had Zika.
A group of Argentinian doctors is arguing that the birth defects are not being caused by Zika at all but by a pesticide put in the water supply of the most affected areas to kill mosquito larva.
The Zika virus infection has been linked to newborn babies with the birth defect microcephaly. This is a congenital condition in which babies are born with unusually tiny heads.
The notion, however, has recently been challenged by a group of Argentine physicians. The group suspects that the Zika virus is not to blame for the rise in microcephaly cases, but that a toxic larvicide introduced into Brazil’s water supplies may be the real culprit.
According to the Physicians in Crop-Sprayed Towns (PCST), a chemical larvicide that produces malformations in mosquitoes was injected into Brazil’s water supplies in 2014 in order to stop the development of mosquito larvae in drinking water tanks.
The chemical, which is known as Pyriproxyfen, was used in a massive government-run program tasked to control the mosquito population in the country. Pyriproxyfen is a larvicide manufactured by Sumitomo Chemical, a company associated [PDF] with Monsanto. However, PCST has referred to Sumitomo as a subsidiary of Monsanto.“Malformations detected in thousands of children from pregnant women living in areas where the Brazilian state added pyriproxyfen to drinking water is not a coincidence,” the PCST wrote [pdf] in the report.
For instance, the Brazilian Health Ministry had injected pyriproxyfen to reservoirs in the state of Pernambuco. In the area, the proliferation of the Aedes aegypti mosquito, which carries the Zika virus, is very high, the PCST said.
Pernambuco is also the first state in Brazil to notice the problem. The state contains 35 percent of the total microcephaly cases in the country.
The group of Argentine doctors points out that during past Zika epidemics, there have not been any cases of microcephaly linked with the virus. In fact, about 75 percent of the population in countries where Zika broke out had been infected by the mosquito-borne virus.
In countries such as Colombia where there are plenty of Zika cases, there are no records of microcephaly linked to Zika, the group said.
When the Colombian president announced that many of the country’s citizens were infected with Zika but that there was not a single case of microcephaly, the allegations soon emerged. Some 3,177 pregnant women in the country were infected with Zika, but the PCST report said these women are carrying healthy fetuses or had given birth to healthy babies.
Researchers, including experts from the U.S. Center for Disease Control, have set up operations in Brazil, seeking to sort all of this out. In the meantime, 90 cases of Zika have been found in the United States, 14 of them spread by sexual transmission. The CDC has found the Zika virus in two babies who died of microcephaly, which looks like a connection, though many questions remain.
HT: Mary Moerbe